Avalon® Interface Specifications

Download PDF
ID 683091
Date 9/26/2022
Public
Document Table of Contents
Document Table of Contents x
1. Introduction to the Avalon® Interface Specifications 2. Avalon® Clock and Reset Interfaces 3. Avalon® Memory-Mapped Interfaces 4. Avalon® Interrupt Interfaces 5. Avalon® Streaming Interfaces 6. Avalon® Streaming Credit Interfaces 7. Avalon® Conduit Interfaces 8. Avalon® Tristate Conduit Interface A. Deprecated Signals B. Document Revision History for the Avalon® Interface Specifications
1. Introduction to the Avalon® Interface Specifications x
1.1. Avalon® Properties and Parameters 1.2. Signal Roles 1.3. Interface Timing 1.4. Example: Avalon® Interfaces in System Designs
2. Avalon® Clock and Reset Interfaces x
2.1. Avalon® Clock Sink Signal Roles 2.2. Clock Sink Properties 2.3. Associated Clock Interfaces 2.4. Avalon® Clock Source Signal Roles 2.5. Clock Source Properties 2.6. Reset Sink 2.7. Reset Sink Interface Properties 2.8. Associated Reset Interfaces 2.9. Reset Source 2.10. Reset Source Interface Properties
3. Avalon® Memory-Mapped Interfaces x
3.1. Introduction to Avalon® Memory-Mapped Interfaces 3.2. Avalon® Memory Mapped Interface Signal Roles 3.3. Interface Properties 3.4. Timing 3.5. Transfers 3.6. Address Alignment 3.7. Avalon® -MM Agent Addressing
3.5. Transfers x
3.5.1. Typical Read and Write Transfers 3.5.2. Transfers Using the waitrequestAllowance Property 3.5.3. Read and Write Transfers with Fixed Wait-States 3.5.4. Pipelined Transfers 3.5.5. Burst Transfers 3.5.6. Read and Write Responses
3.5.2. Transfers Using the waitrequestAllowance Property x
3.5.2.1. waitrequestAllowance Equals Two 3.5.2.2. waitrequestAllowance Equals One 3.5.2.3. waitrequestAllowance Equals Two - Not Recommended 3.5.2.4. waitrequestAllowance Compatibility for Avalon® -MM Host and Agent Interfaces 3.5.2.5. waitrequestAllowance Error Conditions
3.5.4. Pipelined Transfers x
3.5.4.1. Pipelined Read Transfer with Variable Latency 3.5.4.2. Pipelined Read Transfers with Fixed Latency
3.5.5. Burst Transfers x
3.5.5.1. Write Bursts 3.5.5.2. Read Bursts 3.5.5.3. Line–Wrapped Bursts
3.5.6. Read and Write Responses x
3.5.6.1. Transaction Order for Avalon® -MM Read and Write Responses (Hosts and Agents) 3.5.6.2. Avalon® -MM Read and Write Responses Timing Diagram
3.5.6.2. Avalon® -MM Read and Write Responses Timing Diagram x
3.5.6.2.1. minimumResponseLatency Timing Diagram with readdatavalid or writeresponsevalid
4. Avalon® Interrupt Interfaces x
4.1. Interrupt Sender 4.2. Interrupt Receiver
4.1. Interrupt Sender x
4.1.1. Avalon® Interrupt Sender Signal Roles 4.1.2. Interrupt Sender Properties
4.2. Interrupt Receiver x
4.2.1. Avalon® Interrupt Receiver Signal Roles 4.2.2. Interrupt Receiver Properties 4.2.3. Interrupt Timing
5. Avalon® Streaming Interfaces x
5.1. Terms and Concepts 5.2. Avalon® Streaming Interface Signal Roles 5.3. Signal Sequencing and Timing 5.4. Avalon® -ST Interface Properties 5.5. Typical Data Transfers 5.6. Signal Details 5.7. Data Layout 5.8. Data Transfer without Backpressure 5.9. Data Transfer with Backpressure 5.10. Packet Data Transfers 5.11. Signal Details 5.12. Protocol Details
5.3. Signal Sequencing and Timing x
5.3.1. Synchronous Interface 5.3.2. Clock Enables
5.9. Data Transfer with Backpressure x
5.9.1. Data Transfers Using readyLatency and readyAllowance 5.9.2. Data Transfers Using readyLatency
6. Avalon® Streaming Credit Interfaces x
6.1. Terms and Concepts 6.2. Avalon® Streaming Credit Interface Signal Roles 6.3. Avalon® Streaming Credit User Signals
6.2. Avalon® Streaming Credit Interface Signal Roles x
6.2.1. Synchronous Interface 6.2.2. Typical Data Transfers 6.2.3. Returning the Credits
6.3. Avalon® Streaming Credit User Signals x
6.3.1. Per-Symbol User Signal 6.3.2. Per-Packet User Signal
7. Avalon® Conduit Interfaces x
7.1. Avalon® Conduit Signal Roles 7.2. Conduit Properties
8. Avalon® Tristate Conduit Interface x
8.1. Avalon® Tristate Conduit Signal Roles 8.2. Tristate Conduit Properties 8.3. Tristate Conduit Timing
1. Introduction to the Avalon® Interface Specifications
2. Avalon® Clock and Reset Interfaces
3. Avalon® Memory-Mapped Interfaces
4. Avalon® Interrupt Interfaces
5. Avalon® Streaming Interfaces
6. Avalon® Streaming Credit Interfaces
7. Avalon® Conduit Interfaces
8. Avalon® Tristate Conduit Interface
A. Deprecated Signals
B. Document Revision History for the Avalon® Interface Specifications

3.5.5. Burst Transfers

A burst executes multiple transfers as a unit, rather than treating every word independently. Bursts may increase throughput for agent ports that achieve greater efficiency when handling multiple words at a time, such as SDRAM. The net effect of bursting is to lock the arbitration for the duration of the burst. A bursting Avalon® -MM interface that supports both reads and writes must support both read and write bursts.

Bursting Avalon® -MM interfaces include a burstcount output signal. If a agent has a burstcount input, the agent is burst capable.

The burstcount signal behaves as follows:

  • At the start of a burst, burstcount presents the number of sequential transfers in the burst.
  • For width <n> of burstcount, the maximum burst length is 2(<n>-1).The minimum legal burst length is one.

To support agent read bursts, a agent must also support:

  • Wait states with the waitrequest signal.
  • Pipelined transfers with variable latency with the readdatavalid signal.

At the start of a burst, the agent sees the address and a burst length value on burstcount. For a burst with an address of <a> and a burstcount value of <b>, the agent must perform <b> consecutive transfers starting at address <a>. The burst completes after the agent receives (write) or returns (read) the <b th > word of data. The bursting agent must capture address and burstcount only once for each burst. The agent logic must infer the address for all but the first transfers in the burst. A agent can also use the input signal beginbursttransfer, which the interconnect asserts on the first cycle of each burst.


Section Content
Write Bursts
Read Bursts
Line–Wrapped Bursts

Level Two Title